imr 4831

[Doug Casner]

I was loading some 270s 130 gr. 56 gr. of imr 4831. Grain under max. in I think it was a nosler manuel. Using cci 200 primers .Noticed some grains of powder that hadnt burned. Put remington 9.5 . Nowhere on the box does it say the remingtons are magnum but it fixed the problem. Theyre hard to seat. Ive got to start them with my press and finish seating them with a hand priming tool. So they are longer. Are remington 9.5s magnum? They dont shoot as good group wise as the 200s but they burn up the imr 4831. Doug

 

[mmcu]

Remington makes two types of Large Rifle primers.

Their Standard primer is the 9-1/2.
Their Magnum primer is the 9-1/2M.

I'd work up a load using the Standard 9-1/2 primer to determine the accuracy potential of them vs the CCI 200.

 

[Doug Casner]

I shot a 3 shot group that was close to a half in. with the cci primers and 55 gr. of 4831. Went to 56 gr. of 4831 with rem. primers shot an in. but gained about 50 fps. Its a hunting load anyway. Is 4831 hard to burn? I gave up a half inch accuracy for 50 fps. Doug

 

[CJ6]

It can be a primer test for best accuracy.
Once I find a charge that looks promising I'll run several types/brands of primers and see what happens.

 

[mmcu]

I shot a 3 shot group that was close to a half in. with the cci primers and 55 gr. of 4831. Went to 56 gr. of 4831 with rem. primers shot an in. but gained about 50 fps. Its a hunting load anyway. Is 4831 hard to burn? I gave up a half inch accuracy for 50 fps. Doug

If you haven't already done so, I'd drop back down to 55 grains with the Remington 9-1/2 primer and see what kind of accuracy you get compared to your 1/2" load using the CCI 200 primer.

 

[Straightshooter1]

I was loading some 270s 130 gr. 56 gr. of imr 4831. Grain under max. in I think it was a nosler manuel. Using cci 200 primers .Noticed some grains of powder that hadnt burned. Put remington 9.5 . Nowhere on the box does it say the remingtons are magnum but it fixed the problem. Theyre hard to seat. Ive got to start them with my press and finish seating them with a hand priming tool. So they are longer. Are remington 9.5s magnum? They dont shoot as good group wise as the 200s but they burn up the imr 4831. Doug

I shot a 3 shot group that was close to a half in. with the cci primers and 55 gr. of 4831. Went to 56 gr. of 4831 with rem. primers shot an in. but gained about 50 fps. Its a hunting load anyway. Is 4831 hard to burn? I gave up a half inch accuracy for 50 fps. Doug

The CCI200's are softer than the Rem 9.5's and that's probably why they harder to seat . . . and note too that the Rem 9.5's tend to be .005" taller (most of that having to do with the anvil).

Those Rem's of yours are not aa magnum issue, but they do have a lot larger and hotter flash than those CCI's, which can account for some of the velocity difference. This should give you some idea (the BR4's being the same as the 200's):

First one here is the Rem 9.5 and the second the CCI.

 

[ebb]

When I got all my parts back from Col Billy it was a rifle and i set to developing a load I had H4831 and IMR 4831 I got in a trade. The IMR 4831 shoot better groups than the H4831. I eventually went to VV165 and have not bought any of the 4831s in a few years.

 

[jds holler]

I find it odd that looking back in some of my old Speer books that IMR4831 is sometimes listed with CCI 250's and sometimes just 200's. And there seems to be no rhyme or reason to why.

And of course it's anyone's guess as to why it was even called IMR4831, since it must use different data than H4831. (I'll bet that issue has caused some flattened primers and heavy bolt lift )

IMR version came out in '73', and is the hotter of the two, with usually about 2 grains difference in maximum charge weights.

I'd say that when working up a hunting load for either of the 4831s, just use mag primers to establish your load and roll with it. Then you'll be covered for cold weather situations and such. If you aren't getting match accuracy (and need to) then you could always try a kinder and gentler primer. jd

 

[whatsupdoc]

I find it odd that looking back in some of my old Speer books that IMR4831 is sometimes listed with CCI 250's and sometimes just 200's. And there seems to be no rhyme or reason to why.

And of course it's anyone's guess as to why it was even called IMR4831, since it must use different data than H4831. (I'll bet that issue has caused some flattened primers and heavy bolt lift )

IMR version came out in '73', and is the hotter of the two, with usually about 2 grains difference in maximum charge weights.

I'd say that when working up a hunting load for either of the 4831s, just use mag primers to establish your load and roll with it. Then you'll be covered for cold weather situations and such. If you aren't getting match accuracy (and need to) then you could always try a kinder and gentler primer. jd

IMR # 4831 was used to load Oerlikon 20 mm cannon cartridges through World War II. Salvaged powder became available to civilians when the Oerlikon cannon was declared obsolete following the war.[6] Grains of 0.038-inch diameter are 0.083 inches long with 7% DNT coating. IMR # 4831 contains 1.1% diphenylamine (0.5% more than other IMR powders.)

 

[jds holler]

IMR # 4831 was used to load Oerlikon 20 mm cannon cartridges through World War II. Salvaged powder became available to civilians when the Oerlikon cannon was declared obsolete following the war.[6] Grains of 0.038-inch diameter are 0.083 inches long with 7% DNT coating. IMR # 4831 contains 1.1% diphenylamine (0.5% more than other IMR powders.)

So could we assume that it was first packaged and commercially marketed under the name Dupont IMR 4831, in 1973 as my Speer book says?
And just where does H 4831 fall in the history of things? jd

 

[whatsupdoc]

Surplus IMR4831 was sold as Hodgon 4831, when the surplus ran out
Hodgon contracted Nobel in Scotland to copy the surplus IMR4831
this was true H4831. Dupont around 1973 started selling canister grade
IMR4831 to the public.